We are extending our preliminary results of hepatic stem cell purification by using the multiparameter flow cytometric analysis and cell sorting system The system is used to characterize and purify viable hepatic stem cells obtained from rats treated with allyl alcohol. These cells will provide powerful practical and conceptual tools to solve problems of liver organogenesis, function and carcinogenesis. Knowledge gained from this work will facilitate similar studies with human liver tissue. Hepatic stem cells might also serve as key components of regulated multicellular bioreactors. These devices will provide liver function for patients with acute or chronic liver failure.